Luxman SQ-N150 Review (Tube Amplifier)

[MakeMineVinyl]

Not sure I agree. Tell me of another tube amp in the 10W game that measures better. This is clearly designed for a narrow audience. Many tube designs are fake tube designs that kinda keep tubes in the preamp section but really amp stuff up in solid state. It's cheaper and makes it easier to pass homologation.

My 2A3 single ended triode amplifier does way better than the Luxman reviewed here. The THD is something like 0.03%.

 

[Ken Tajalli]

Problem is not preference, it's that within the design paradigm, this is implemented poorly.

I said that a while ago, people disagreed with me.

I still think the output stage is not balanced correctly (there is a fault with this unit).
All that PSU noise and heavy 2nd harmonic, is pointing the finger at.
Am I onto something?

 

[Doodski]

I said that a while ago, people disagreed with me.

View attachment 214151

I still think the output stage is not balanced correctly (there is a fault with this unit).
All that PSU noise and heavy 2nd harmonic, is pointing the finger at.
Am I onto something?

Perhaps sending the unit back to Luxman for warranty service would prove that to be true. Have them service it and then get it tested by @amirm a second time.

 

[MAB]

Not sure I agree. Tell me of another tube amp in the 10W game that measures better.

This was demonstrated early in this thread. The example was a classic that a Luxman of that era should have competed against. The old Dynaco smoked this modern Luxman.

Just for giggles, I put my Dynaco SCA-35 power amp section which I built into the chassis below on my bench. This amplifier uses the same output tubes as the Luxman and can do 17 watts per channel. I set up my 'dashboard' and the results are below. This half-century-old Dynaco beats the Luxman at the same measurement conditions. The THD is 0.08145% and the THD+N is 0.11096% - easily beating the far more expensive Luxman. You can see that there is still a strong 2nd order harmonic distortion present in this amp where ideally there should be very little, but it still beats the Luxman.

Fail for team Luxman.

View attachment 212899


View attachment 212900

 

[pablolie]

I said that a while ago, people disagreed with me.

View attachment 214151

I still think the output stage is not balanced correctly (there is a fault with this unit).
All that PSU noise and heavy 2nd harmonic, is pointing the finger at.
Am I onto something?

Perhaps... but aren't 2nd harmonics the whole point of tube amps these days? Isn't that exactly why some love them?

 

[pablolie]

This was demonstrated early in this thread. The example was a classic that a Luxman of that era should have competed against. The old Dynaco smoked this modern Luxman.

And I replied. The old Dynaco would not pass any homologation test these days, IMO (I did omit the product name to not offend anyone). Plus, seriously, if that is the perfect measurement chart and you're setting that as a standard... remind me if Amir recommended it? you know that's just being biased. :-D

 

[pseudoid]

Nor do I know nor do I care.

You convinced me to change my vote to #3.
Only because I know what it is to live w/an original issue Mc275 for over a decade.
Era-correct; the Mac had similar THD levels like this Luxman SQ-N150 but the Mc275 design goes back to early 1960s.
Early '80s, Micheal Bettinger (GASWorks) converted my power-supply and ground-networks to 'dual-mono', added a new bias ckt. etc.
Even if the results were psychosomatic (or even hypochondriacal), my upgraded Mac had a "cleaner" sound by far.

 

[pablolie]

You convinced me to change my vote to #3.
Only because I know what it is to live w/an original issue Mc275 for over a decade.
Era-correct; the Mac had similar THD levels like this Luxman SQ-N150 but the Mc275 design goes back to early 1960s.
Early '80s, Micheal Bettinger (GASWorks) converted my power-supply and ground-networks to 'dual-mono', added a new bias ckt. etc.
Even if the results were psychosomatic (or even hypochondriacal), my upgraded Mac had a "cleaner" sound by far.

I hope you know I am not in opposition of your point.

 

[MAB]

And I replied. The old Dynaco would not pass any homologation test these days, IMO (I did omit the product name to not offend anyone). Plus, seriously, if that is the perfect measurement chart and you're setting that as a standard... remind me if Amir recommended it? you know that's just being biased. :-D

So... There is something unique about that Dynaco that gave it an unfair advantage? What uniquely prevents it from 'homologation'? And that disqualifies the measurements? (I wanna say tube-PEDs) On a technicality like this? It just shows really how poor this amp is. It is not alone, lots of these things have cropped up, and Luxman is one of the brands that is filling the vacuum. Too bad, I am a big fan of vintage Luxman, and I have several old school Luxman pieces I prize, and this is none of that...

Perhaps... but aren't 2nd harmonics the whole point of tube amps these days? Isn't that exactly why some love them?

Perhaps this is easy to confuse. The harmonic distortion this unit demonstrates is not the euphonic type people want. It is the power supply ringing the output stage. That distortion shows up as even harmonics (because of the nature of the tubes), but the source is not the music but rather the power supply.

The Dynaco has none of this, just the even harmonics intrinsic to this tube implementation. The Dynaco is properly designed to minimize these issues that the Luxman has.

 

[levimax]

You convinced me to change my vote to #3.
Only because I know what it is to live w/an original issue Mc275 for over a decade.
Era-correct; the Mac had similar THD levels like this Luxman SQ-N150 but the Mc275 design goes back to early 1960s.
Early '80s, Micheal Bettinger (GASWorks) converted my power-supply and ground-networks to 'dual-mono', added a new bias ckt. etc.
Even if the results were psychosomatic (or even hypochondriacal), my upgraded Mac had a "cleaner" sound by far.

According to this review a stock Mc275 has far less distortion than the Luxman https://www.stereophile.com/content/mcintosh-mc275-power-amplifier-measurements

 

[BDWoody]

According to this review a stock Mc275 has far less distortion than the Luxman https://www.stereophile.com/content/mcintosh-mc275-power-amplifier-measurements

That was back when they were trying to minimize distortion, not turn it into a selling point.

Here are a couple of ads from the day. Focus seems to be on fidelity, not a pleasing distortion profile.

 

[MakeMineVinyl]

Perhaps... but aren't 2nd harmonics the whole point of tube amps these days? Isn't that exactly why some love them?

Unfortunately high 2nd harmonics is the point of many amplifiers made today, but that is not how it should be nor has to be. Imagine that every record you purchased (if you purchased records) had mixed in the sound of severe ticks and pops that you couldn't defeat so that it 'sounds like a record'. Amplifiers with intentionally high distortion are just as silly.

And note that this is not only happens with tubes, but solid state amplifiers as well - even hyper expensive ones. Just look at the measurements and graphs of the distortion of this monstrosity.

The point is that amplifiers like the Luxman and others which intentionally have high distortion in order to pander to the perceived market of today should be firmly called out in places like ASR. Somebody has to call out intentionally defective designs like this as a dumbing-down of the goals of High Fidelity.

Being on this site, I assume that you're interested in something resembling the best and truest reproduction you pay your money for. If ASR can call attention to purposefully hobbled designs so that people seeking advise on their purchases can avoid them, so much the better.

 

[MakeMineVinyl]

That was back when they were trying to minimize distortion, not turn it into a selling point.

Here are a couple of ads from the day. Focus seems to be on fidelity, not a pleasing distortion profile.

View attachment 214155

View attachment 214154

I don't know off hand what the distortion in a test with the same operating levels the Mac has, but I am certain it is nowhere near 0.4% like the Luxman.

 

[SIY]

Perhaps... but aren't 2nd harmonics the whole point of tube amps these days? Isn't that exactly why some love them?

In ad copy or for real? You do understand that properly adjusted push pull tube amps have very low second?

 

[SIY]

I still think the output stage is not balanced correctly (there is a fault with this unit).

Non-matched output tubes is still the most likely.

 

[MakeMineVinyl]

Non-matched output tubes is still the most likely.

The tubes are fine. Its the designer tube sockets which are not matched.

 

[Mart68]

Not sure I agree. Tell me of another tube amp in the 10W game that measures better.

Radford STA15 https://www.radfordrevival.co.uk/sta-reissue/specifications/

 

[Pirx]

Perhaps... but aren't 2nd harmonics the whole point of tube amps these days? Isn't that exactly why some love them?

The 2nd harmonic should not dominate in properly designed Push-Pull construction.
This is kind of operation where the 2nd harmonic from both EL84 should cancel in output transformer and we should see the 3rd dominating, but ofc much, much lower than this Luxman.
That amplifier should not represent "tube world" in any case but the look.

 

[Ken Tajalli]

The tubes are fine. Its the designer tube sockets which are not matched.

Can you elaborate please.
Thanx

 

[egellings]

Homologation?